Indicator System For Goods And Services

ABSTRACT

An indicator system with a blocked state and an unblocked state is disclosed. The indicator system may be used in conjunction with packaged products, packaging materials, medical products, films, biological assays and diagnostics, identification badges, and/or security passes. The indicator system responds to a triggering stimulus once unblocked. The respond is observable through a color change that may include a change form colorless to colored, colored to colorless, and/or colored to colored. The indicator system in its blocked state is substantially unreactive with the triggering stimulus.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. 120 and is acontinuation-in-part of U.S. patent application Ser. No. 11/273,805,filed Nov. 14, 2005, which claims priority to and is a continuation ofU.S. patent application Ser. No. 10/651,627, filed Aug. 29, 2003, nowU.S. Pat. No. 7,026,029, which claimed priority under 35 U.S.C. 119 toU.S. Provisional Patent Application No. 60/415,480, filed Oct. 2, 2002,and is a continuation-in-part of U.S. patent application Ser. No.10/163/473, filed Jun. 5, 2002, which claimed priority to U.S.Provisional Patent Application No. 60/295,903, filed Jun. 5, 2001, allof which are incorporated by reference herein in their entirety. Thisapplication also claims priority under 35 U.S.C. 120 and is acontinuation-in-part of U.S. patent application Ser. Nos. 11/273,804;11/274,392; 11/274,550; 11/274,743; and 11/274,865, all of which werefiled on Nov. 14, 2005, and all of which claim priority under 35 U.S.C.119 to U.S. Provisional Patent Application No. 60/627,787, filed Nov.12, 2004; U.S. Provisional Patent Application No. 60/627,638, filed Nov.12, 2004; U.S. Provisional Patent Application No. 60/627,209, filed Nov.12, 2004; U.S. Provisional Patent Application No. 60/627,386, filed Nov.12, 2004; and U.S. Provisional Patent Application No. 60/711,616, filedAug. 26, 2005, all of which are hereby incorporated by reference as ifset forth herein in their entirety. This application also claimspriority under 35 U.S.C. 119 to U.S. Provisional Patent Application No.60/672,610, filed Apr. 19, 2005, the disclosure of which is incorporatedby reference herein in its entirety.

FIELD OF INVENTION

The present invention is directed to an indicator system(s) and methodsof using same.

SUMMARY OF INVENTION

A colorimetric indicator system including a reactive material that has afirst state that is substantially unreactive to the presence of oxygenand a second state that is substantially reactive to the presence ofoxygen. The first state includes at least one blocked dye derived by thereduction of a dye selected from azines, oxazines, thiazines, andcombinations thereof; and said second state comprises said at least oneblocked dye unblocked, where the blocked dye is derived by the reductionof a dye having the formula (I):

wherein Y represents O, S, or NR₁₂, wherein R₁₂ is selected fromhydrogen, alkyl, or aryl groups; Z is selected form NR₉ R₁₀, OR₁₁,hydrogen, alkyl, aryl, azo, or fused aromatic components: R₁, R₂, R₃,R₄, R₅, and R₆ each independently is selected from hydrogen, alkyl oraryl groups; and X— represents a halogen or other suitable anion. Thecolorimetric indicator of the present invention is affixed to an/orintegral with at least one of a package wall, a packaged object, anidentification badge, and a substrate. Where substrate is inclusive ofanything that holds or serves as a foundation, base, point ofattachment, backing, back, or support for the reactive material.

A colorimetric indicator system including a reactive material that has afirst state that is substantially unreactive to the presence of oxygenand a second state that is substantially reactive to the presence ofoxygen. The first state includes at least one blocked dye derived by thereduction of a dye having the formula III, and combinations thereof; andsaid second state comprises said at least one blocked dye unblocked,where the blocked dye is derived by the reduction of a dye having theformula (III):

wherein R₁-R₄, R₇ each independently is selected from hydrogen, alkyl,aryl, alkoxy, halogens, hydroxyl, CN, substituted thiols, SO₂ alkyl, SO₂aryl, CO₂ alkyl, or CO₂ aryl, where alkyl and aryl can be substitutedand may include atoms necessary to complete an aromatic or acyclic ringsystem, which may contain heteroatoms and substitution; R₅, R₆ eachindependently is selected from hydrogen, alkyl, aryl, alkoxy, wherealkyl and aryl can be substituted and may include atoms necessary tocomplete an aromatic or acyclic ring system. The colorimetric indicatorof the present invention is affixed to and/or integral with at least oneof a package wall, a packaged object, an identification badge, and asubstrate. Where substrate is inclusive of anything that holds or servesas a foundation, base, point of attachment, backing, back, or supportfor the reactive material.

An advantage of the disclosed indicator system(s) and applications isthat the indicator system(s) can be applied to a package and/or goodand/or service and/or item in a blocked form i.e., substantiallyunreactive to a triggering stimulus. For example, the indicatorsystem(s) may be printed on a substrate in the presence of itstriggering stimulus and not undergo is observable change untilunblocked. The blocking group also imparts characteristics that greatlyenhance the solubility of the indicators in organic solvents andmonomers/polymers thus increasing their ease of application.

It is contemplated that the various embodiments and elements describedherein can be used in combination. All manner of attaching the indicatorsystem are contemplated by the present invention. Moreover, it iscontemplated that the indicator system can have any shape or size.

Persons skilled in the art will recognize that there may be differentdevices, mechanism, and methods of operation that are within the spiritand scope of the invention herein disclosed. Also, it should beunderstood that the drawings, while useful for illustrating theinvention, are not intended to be necessarily to scale. To the extentthat drawings imply dimensions and relative size positions, the drawingsshould be regarded as illustrative only and not limiting the inventionto particular dimensions, sizes, positions, and location of parts.

The below disclosure employs the term substrate to describe a number ofdisclosed embodiments. Substrate means any surface and/or boundary,where internal and/or external and/or interstitial, for which theindicator system is and/or can be placed and/or affixed and/or otherwiseattached. A substrate may be rigid, flexible, transparent, opaque,linear, curved, flat, elliptical and/or combinations thereof. Forexample, substrate includes, for example, the surface or at least aportion thereof of a good and/or service and/or item and/or package.Moreover, the use of substrate in the present disclosure encompassessystems in which the indicator system is integral and/or sandwichedbetween two layers of materials, such as, for example, a film.

DETAILED DESCRIPTION

Package Integrity

One embodiment consistent with the present invention is directed to asystem for determining whether the anaerobic seal on a package and/ordevice has been compromised and its contents exposed to air. Thisembodiment may be used in conjunction with packages used in the good,pharmaceutical and medicinal industries and others which can becompromised by tampering or exposure to the atmosphere or which maydeteriorate due to the presence of oxygen. This embodiment permitsevaluation of such oxygen sensitive materials without liberating themfrom a package. For example, a cardiac stent after being manufacturedand packaged under sterile conditions has to be shipped to a hospital orother like facility where it will be applied to a patient. It is usefulto the physicians performing the procedures that they can ascertain thesterility of the stent and associated package and whether the integrityof the package was breached from the time it was sent from themanufacturing facility to the facility where the procedure is to beperformed. The present embodiment is directed to a package system,wherein the package includes an indicator system. The indicator systemis initially in a first state. For example, the first sate is asubstantially transparent state. The indicator system transforms to asecond state upon the happening of a triggering event and/or after apredetermined period of time. For example, the second state is a coloredstate and/or substantially non-transparent state. If the package iscompromised and/or otherwise fails, the indicator system transitionsfrom a first state to a second state wherein the transition andresultant second state is detectable and/or observable. The indicatorsystem can be applied to the package in a number of ways, all of whichare readily available and known in the art. For example, the indicatorsystem can be printed, i.e., via an ink jet printer, contact print, spotapplication, or any number of application methods, on one of the layersand/or surfaces that make up the internal boundary of the package;adhered to one of the layers and/or surfaces that make up the internalboundary of the package; and/or integral to the packaging materialitself.

Times Out Applications

A further and overlapping embodiment consistent with the presentinvention is directed to a system for timing out the validity and/orusefulness of a product and/or device and/or item. The applications ofthis embodiment are legion. For example, visitors to a building an/ordocument facility are typically given an access badge and/or pass. Thesebadges and/or passes are typically provided for a predefined period oftime, thus they have a limited useful life, i.e., a one day pass to alibrary archive. The badges and/or passes are printed, at least in part,with the indicator system. The indicator system has a first state and asecond state. After a predetermined time the indicator systemtransitions from its first state to its second state. The transition canbe from one color to another and/or colored to clear and/or clear tocolored. Alternatively, the indicator systems spell out a word and/orphrase on the badge and/or pass. The word and/or phrase is initiallysubstantially clear. After a predefined time the word an/or phrasebecomes visibly observable. At such time the badge and/or pass is notlonger valid. A further example includes, a document that includes andoffer that expires after a day or price quotes that are only valid for aweek. The offer that is to expire and/or the price quotes are printedusing the indicator system of the present invention. The indicatorsystem has a first state and a second state. After a predetermined timethe indicator system transitions from its first state to its secondstate. The transition can be form one color to another and/or colored toclear and/or clear to colored.

Shelf Life

A yet further and overlapping embodiment of the present invention isdirected to a system for determining the potability and/or consumabilityand/or shelf life of food. For example, fresh meats and vegetables havea finite life span in which they need to be prepared and consumed beforethey spoil. All spoilage is not detectable by the eye. In some instancesfood that has spoiled is consumed and results in sickness and/or illnessand in some instances death. To increase the shelf life of food therehave been great development strides in packaging materials, includingfilms and preformed trays and anaerobic packaging. However, sincepackaged foods are transported to their retail destinations and handleda number of times in stock there exists a danger that the package mightbecome compromised, thereby shortening the intended shelf life of thefood. Alternatively, a retailer may not be entirely honest or with nomalice intended, leave the food item out beyond its shelf life. In theabove situations it would be beneficial to consumers if there was yetanother layer of protection. The present invention provides an indicatorsystem for conveying the potability and/or consumability and/or shelflife of food. For example, the indicator system is a dot thattransitions from a first state to a second state. The first state issubstantially transparent. The second state is substantially opaqueand/or colored so as to be detectable by the consumer. The transitionoccurs after exposure to a predefined stimulus, such as for exampleoxygen, and/or after a predefined period of time. Alternatively, theindicator system may take the form of a word and/or phrase. The wordand/or phrase being initially substantially transparent andtransitioning to a substantially opaque and/or colored state. Theindicator system can take many different configurations, including forexample, an indicator dye in communication with a scavenger material.After the scavenger material is exhausted the indicator dye transitionsfrom its first state to a second state, thereby providing a predefinedshelf life for a packaged product. Alternatively, the indicator systemoperates independently of a scavenger material. The indicator system canbe applied to the package in a number of ways, all of which are readilyavailable and known in the art. For example, the indicator system can beprinted, i.e., via an ink jet printer, contact print, spot application,or any number of application methods, on one of the layers and/orsurfaces that make up the internal boundary of the package; adhered toone of the layers and/or surfaces that make up the internal boundary ofthe package; and/or integral to the packaging material itself.

Cellular and/or Biotechnology Assays, Tests, and/or Diagnostics

In another embodiment of the present invention, the indicator system canbe used to monitor redox activity in cells and tissues. Since reactiveoxygen species are produced only by live cells the indicators can alsoprovide a means for determining cell viability. The indicator system hasa first state and a second state and transitions from its first state toits second state following enzymatic activity and interaction withreactive oxygen species. The transition can be from one color to anotherand/or colored to clear and/or clear to colored. The transition can alsobe from fluorescent to non-fluorescent or non-fluorescent tofluorescent.

Archive Material Monitoring System

A further and overlapping embodiment of the present embodiment isdirected to an indicator system for the preservation of works of artand/or other oxygen sensitive works from antiquities. Certain types ofartistic media are sensitive to oxygen and/or readily oxidizable. Thissensitivity can cause colors to fade. To this end certain works of artand/or documents from antiquity are stored and/or preserved in oxygenfree and/or climate controlled environments. The indicator system of thepresent embodiment allows the environments to be monitored for changes.The indicator system of the present embodiment has a first state and asecond state. Upon environmental changes of a deleterious nature theindicator system transitions from a first state to a second state. Thetransition is observable.

Security Application

Another and overlapping embodiment of the present invention is directedto a security system for a packaged good and/or service and/or document.An indicator system is affixed to the packaged good and/or serviceand/or document. A barrier layer and/or package prevents access to thegood and/or service and/or document. Once the barrier layer and/orpackage is compromised the indicator system transitions from a firststate to a second state. The transition is observable. The indicatorsystem can be affixed and/or integrated with the good and/or serviceand/or document such that it can not be removed without damaging thegood and/or service and/or document. The indicator system provides asystem for the indication of whether tampering and/or access and/orunauthorized access has occurred. The indicator system can be applied tothe good and/or service and/or document in a number of ways, all ofwhich are readily available and known in the art. For example, theindicator system can be printed, i.e., via an ink jet printer, contactprint, spot application, or any number of application methods, on one ofthe layers and/or surfaces that make up the good and/or service and/ordocument; adhered to one of the layers and/or surfaces that make up thegood and/or service and/or document; and/or integral to the good and/orservice and/or document. The indicator system provides a way fordetermining whether an item has been tampered with and/or whether it wasaccessed outside proper protocol.

Medical Application

Another and overlapping embodiment of the present invention is directedto an indicator system for determining whether an item has been exposedto a sterilization oxidant. In this embodiment the indicator system isattached and/or affixed and/or in communication with the item. After theitem is exposed to a sterilization oxidant the indicator transitionsfrom a first state to a second state. The transition is observableand/or detectable.

Barcode Application

Yet another overlapping embodiment consistent with the present inventionincludes the use of the indicator system in conjunction with one or morebarcodes. The barcodes may, for example, be those associated with aretail product—such as a consumable good or for tracking a package or anidentification pass and/or badge. The indicator system is placed incommunication with a least one barcode. After a predefined period oftime or predetermined event the indicator system acts to prevent thebarcode from being read by a barcode scanner and/or reader. For example,the indicator system may be placed in communication with a barcode underwhich a perishable item is packaged—for example meat. After apredetermined time and as determined by the shelf life of the good theindicator system transitions to a state that prevents the barcode frombeing read and thus indicating to a cashier or barcode scanner operatorthat the good is not longer sellable and/or good.

Indicator Materials

In one embodiment of the present invention, the stimulus triggering thereaction is exposure to atmospheric oxygen. Upon exposure to oxygen, areactive material, e.g., leuco methylene blue, which is essentiallycolorless, is oxidized to form an opaque or semi-opaque state (e.g., thedeep blue dye, methylene blue). By adjusting the time it takes to turnopaque, this method can be used to provide the contemplatedapplications.

Possible reactive materials include, but are not limited to, oxygensensitive leuco or reduced forms of phenothiazines, phenoxazines, andphenazinies, whose members include: Methylene Blue, Brilliant CresylBlue, Basic Blue 3, Methylene Green, Taylor's Blue, Meldola's Blue, NewMethylene Blue, Thionin, Nile Blue, Celestine Blue, and Toluidine 0, aswell as reaction products and combinations comprising at least one ofthe foregoing material; the structures of which are set forth below:

A method for the synthesis of leucomethylene blue and the oxygendependent reoxidation to form the colored form of the methylene blue dyeis illustrated below and be found in more detail in U.S. Pat. No.7,026,029, herein after incorporated by reference in its entirety.

In addition to the above reactive materials, numerous dyes can besynthesized to operate in accordance with the above disclosedapplications. For example, some other possible reactive materials can befound in U.S. Pat. No. 4,404,257, hereafter incorporated by reference,and U.S. Pat. No. 5,815,484, hereafter incorporated by reference; bothin their entirety. Additional examples include.

(a) leuco-azine dyes., such as those disclosed in U.S. Pat. No.4,710,570, herein incorporated by reference in its entirety.

in which:

X is O, S, NR₂

Z completes a fused aromatic or hetercyclic ring system

N is 0 or 1 to allow one R¹ ring substituent

Q represents CR₄R₅ in which at least one of R₄ and R₅ is anelectronegative group or R₄ and R₅ may complete a ring, or when X is S,Q may represent NR₃ in which R₃ is an aromatic or heterocyclic group.

(b) quinoneimines, including indamines, indophenols, and indoanilines,such as those disclosed in U.S. Pat. No. 5,424,475, herein incorporatedby reference in its entirety and for example, include the following:

where X, Y, and Z can be but are not limited to: hydrogen, alkyl,alkoxy, aryl, substituted alkyl, alkoxy, and aryl, OH, CN, halogens,NR₆R₇, SR₈R₉ where R₂-R₉ may be hydrogen alkyl, aryl, substituted alkylor aryl, or may represent the atoms necessary to complete an aromatic oracyclic ring system which may contain heteroatoms and substitution.

(c) anthraquinones; and include, for example,

where R₁ and R₂ can be but are not limited to: hydrogen, alkyl, alkoxy,aryl, substituted alkyl, alkoxy, and aryl, OH, CN, halogens, NR₅R₆, SR₇,SO₂R₈ where R₅-R₈ may be hydrogen, alkyl, aryl, substituted alkyl oraryl, or may represent the atoms necessary to complete an aromatic oracyclic ring system which may contain heteroatoms and substitution.

(d) acridinies; and include, for example,

where R₁-R₄ call be but are not limited to: hydrogen, alkyl, aryl,substituted alkyl or aryl, or may represent the atoms necessary tocomplete an aromatic or acyclic ring system which may containheteroatoms with substitution, and R₅ can be but is not limited to:hydrogen, alkyl, aryl, substituted alkyl and aryl groups.

(e) and di- and triarylmethane dyes, such as those disclosed in U.S.Pat. No. 5,330,864 and herein incorporated by reference in its entiretyand include for example,

where X and Y can be but are not limited to: hydrogen, alkyl, alkoxy,aryl, substituted alkyl, alkoxy and aryl, OH, CN, halogens, NR₆R₇, SR₈,SO₂R₉ where R₂-R₇ may be hydrogen alkyl, aryl, substituted alkyl oraryl, or may represent the atoms necessary to complete all aromatic oracyclic ring system which may contain heteroatoms and substitution. Itis understood that R1 can be a substituted aryl.

Additional reactive materials include, but are not limited to, pHindicator materials, materials that undergo photopolymerization,materials that produce precipitates, and light activated chemistries.

By using reactive materials that absorb at different wavelengths it ispossible to prepare indicators of varying color. These indicators may becombined to produce a mixed indicator that can be used as a timing agentfor the above disclosed applications. The individual indicators in a mixcan respond to the same trigger but at different time intervals or theycan respond to different triggers at different time intervals changingfrom a first state to a second state. For example, the first state is asubstantially transparent state. The indicator system transforms to asecond state upon the happening of a triggering event and/or after apredetermined period of time. For example, the second state is a coloredstate and/or substantially non-transparent state. As an example, thefollowing aminonaphthoquinones absorbs in the blue region of the visiblespectrum.

wherein

R₁-R₄, R₇ each independently is selected from hydrogen, alkyl, aryl,alkoxy, halogens, hydroxyl, CN, substituted thiols, SO₂ alkyl, SO₂ aryl,CO₂ alkyl, or CO₂ aryl, where alkyl and aryl can be substituted an mayinclude atoms necessary to complete an aromatic or acyclic ring system,which may contain heteroatoms and substitution;

R₅, R₆ each independently is selected from hydrogen, alkyl, aryl,alkoxy, where alkyl and aryl can be substituted and may include atomsnecessary to complete an aromatic or acyclic ring system.

The synthesis of these type compounds as well as other classes of dyesthat absorb in this region can be found in pending U.S. application Ser.Nod. 11/273,804 filed on Nov. 14, 2005; 11/273,805 filed on Nov. 14,2005; 11/274,392 filed on Nov. 14, 2005; 11/274,550 filed on Nov. 14,2005; 11/274,743 filed on Nov. 14, 2005; and 11/274,865 filed on Nov.14, 2005 all of which are herein incorporated by reference in theirentirety.

The reactive materials can further comprise a mixture comprising atleast one of any of the above mentioned reactive materials.

In one embodiment of the present invention, the reactive material ismixed with a carrier for deposition on and/or impregnation into at leasta portion of the surface of the substrate. Possible carriers comprisethe thermoplastic acrylic polymers, polyester resins, epoxy resins,polythiolenes, UV curable organic resins, polyurethanes, thermosettableacrylic polymers, alkyds, vinyl resins and the like, as well ascombinations comprising at least one of the foregoing carriers.Polyesters include, for example the reaction products of aliphaticdicarboxylic acids including, e.g., fumaric or maleic acid with glycols,such as ethyleneglycol, propyleneglycol, neopentylglycol, and the like,as well as reaction products and mixtures comprising at least one of theforegoing.

Some epoxy resins, which can be used as the organic resin, includemonomeric, dimeric, oligomeric, or polymeric epoxy material containingone or a plurality of epoxy functional groups. For example, reactionproducts of bis phenol-A and epichlorohydrin, or the epichlorohydrinwith phenol-formaldehyde resins, and the like. Other organic resins canbe in the form of mixtures of polyolefin and polythiols, such as shownby Kehr et al, U.S. Pat. No. 3,697,395 and U.S. Pat. No. 3,697,402,hereafter incorporated by reference.

Optionally, the reactive layer and/or material can be applied to thesubstrate using various coating techniques such as painting, dipping,spraying, spin coating, screen printing, ink jet printing, and the like.For example, the reactive layer and/or material can be mixed with arelatively volatile solvent, preferably an organic solvent, which iscapable of dissolving the carrier. Examples of some suitable organicsolvents include ethylene glycol diacetate, butoxyethanol, the loweralkanols, and the like.

For surface coatings, the reactive layer and/or material may alsooptionally contain various additives such as flatting agents, surfaceactive agents, thixotropic agents, and the like, and reaction productsand combinations comprising at least one of the foregoing additives. Thethickness of the reactive layer and/or material is dependent upon theparticular reactive material employed, the concentration thereof in thereactive layer and/or material, and the desired absorptioncharacteristics of the layer both initially and after a desired periodof time.

Development of Blocked Reactive Compounds

One embodiment of the present invention is the use of blocked forms ofthe reactive compounds in the reactive layer and/or material. Thesecompounds will unblock within a predetermined time period after the goodand/or service and/or item is manufactured and/or packaged and/orprinted, and typically before the good an/or service and/or item is usedby the consumer. This is desirable when the stimulus that triggers thereaction can trigger this reaction during the manufacturing of the goodand/or service and/or item, and thus measures need to be taken so thatthe reactive compound is not activated during the manufacturing of thegood and/or service and/or item. For example, in the case of oxygentriggered reactions, unless a blocked form of the reactive compound isused, manufacturing may need to take place in an oxygen freeenvironment, such as a nitrogen atmosphere.

One embodiment of the present invention comprises the use of achemically blocked an/or modified and/or protected reactivesubstance(s). Specific exemplary blocked dyes and methods of preparingdye precursors are disclosed. Leuco dye precursors, which permit thedeblocking, and oxidation of the leuco dye precursors at acceptablerates and methods of applying dyes and dye precursors to a good and/orservice and/or items both on the surface of the good and/or serviceand/or items and/or package surface are. disclosed herein and in U.S.Pat. No. 7,026,029, herein incorporated by reference in its entirety.Also disclosed is the use of bases to increase the rate of methyleneblue generation in blocked leuco dye-containing layers in or an opticalgood and/or service and/or items.

All of the problems discussed in the previous two paragraphs could beavoided if the leuco dye could be coated in a solventless, light orradiation cured (hereafter called generically “UV-cured”) layer and/orarea. The major obstacle to creating such a system is that many leucodyes, and in particular leucomethylene blue (hereafter “LMB”), inhibitboth radical and cationic polymerization reactions of the type used tocure UV-curable monomers such as the acrylates. The oxidized dyes(including methylene blue) also are inhibitors of such polymerizationreactions. So putting a leuco dye (which will contain some of theoxidized, colored dye) in a UV-curable composition will either preventthe UV-curing from taking place, or slow the UV-curing and make theprocess much less economical. Moreover, the process of UV-curing canresult in some of the leuco-dye becoming oxidized if any oxygen and/orother oxidizing agent is present in the layer to be cured, resulting ina produce prematurely containing oxidized dye.

Blocked versions of leucomethylene blue are known and have been used insuch applications, and one such compound at least,benzoyl-leucomethylene blue (BLMB), is commercially available. However,it has been found that BLMB does not deblock easily enough to yield anacceptable good and/or service and/or item. Other blocked leucomethyleneblue compounds share this problem or deblock too easily such thatoxidizable leucomethylene blue is generated in the coating fluid beforeit is desired.

It has been found that triisopropylsilyloxycarbonylleucomethylene blue(hereafter “TIPSOCLMB”), whose structure and exemplary synthesis aredisclosed in U.S. Pat. No. 7,026,029, herein incorporated by referencein its entirety, has the following desirable properties.

1. It is readily synthesized in two steps from commercially availablestaring materials. By isolating and purifying the BOC-LMB produced inthe first step the TIPSOCLMB is prepared from a pure compound ratherthan from the typically very impure methylene blue.

2. It can be incorporated into an acrylate formulation described inExample 1 in which it is stable in its original blocked form for up to ayear at temperatures below 0 degree C, allowing coating formulations tobe prepared at one facility and shipped to another facility, if desired.

3. It can be deblocked in a period of a week or less, presumably by ahydrolysis reaction involving water or other nucleophiles which caneither be provided in the acrylate formulation or be absorbed from theatmosphere in which the good and/or service and/or item is manufacturedor in the packaging material. Nucleophiles that have shown utility fordeblocking are fluoride ion and carboxylate ion, both of which candeblock under essentially neutral pH conditions.

4. The deblocked LMB is stable (to oxidation to methylene blue) in theabsence of oxygen. The rate at which the deblocked LMB oxidizes in thepresence of oxygen can be controlled by regulating the effective pH ofthe coating formulation. It is known in the art that the rate ofoxidation of LMB increases as the pH of its environment increases. Thusthe rate of oxidation can be increased by the addition of basicsubstances that are soluble in the matrix containing deblocked orblocked LMB and which do not react with the matrix or substrate used.One such basic compound is DABCO (1,4-diazabicyclo[2.2.2]octane), anamine. Other amines may be added or substituted. Further, the additionof a strong protic acid such as, for example, camphorsulfonic aciddecreases the rate of LMB oxidation in a polymer film.

5. In the absence of water or other nucleophiles, it is a stable solidwhich can be stored after synthesis for at least several months, even inthe presence of oxygen. Acrylate-based coating fluids containingTIPSOCLMB can be handled in the presence of oxygen until the deblockingreaction has taken place, this reaction is slow enough that the handlingof the coating fluid during the manufacturing processes can be done innormal (undried) air and is not difficult.

EXAMPLE 1

Formulation of Surface Coating Fluid Containing TIPSOCLMB

80 mg TIPSOCLMB80 mg Irgacure 819 (Ciba Geigy; sensitizer) 4.0 ml CD-501acrylate (Sartomer; propoxylated [6] trimethylopropanetriacrylate) 18.5mg 1,4-diazabicycle[2.2.2]octane (“Dabco”, Aldrich; base) 155 mul1,1,1,3,3,3-hexamethyldisilazane (““HMDZ”; Aldrich”; stabilizer)

The TIPSOCLMB, Irgacure 819, and Dabco are weighed into a brown glassbottle, a stir bar is added, the CD-501 is poured in to the properweight, and the HMDZ is added by syringe. Dry nitrogen is blown into thebottle for a few minutes and the bottle is capped and the cap covered byparafilm. The contents are stirred at room temperature for at least twohours to dissolve the solids. If not all of the material is used, blowthe bottle with nitrogen, cap and seal with parafilm, and store in afreezer; warm the bottle before opening to prevent water from condensingin the bottle.

EXAMPLE 2

Preparation of Disk Surface-Coated with TIPSOCLMB/Acrylate Formulation

A substrate is centered on a laboratory spin coating turntable rotatingat roughly 60 rpm's. A 4 ml solution from example #5 is then applieduniformly in a circular ring by a syringe at about a 34 to 40 mmdiameter from the center of the substrate an/or good and/or serviceand/or item. The spin speed is then rapidly increased to about 200 rpmfor about 15 seconds, resulting in a coating of acrylate/TIPSOCLMB fluidabout five .mu.m thick. The spinning is slowed; excess fluid wiped offthe edge with a tissue and base solvent, if available, and then removedto a lab bench. At this point, the good and/or service and/or itemand/or substrate is subjected to about five flashes from a Norlite 400xenon flash lamp at its max setting. The time between flashes isdictated by the charging of the flash lamp, but should be sufficient asto not induce added stress from heat generated in the cure (typicallyabout 5 seconds). This process will yield a clear, uncolored, fullycured acrylate film. Other substrates were also prepared with similaracrylate formulations that contain either no Dabco or 10 times theamount of Dabco described in Example 1.

The TIPSOCLMB formulations from Example 1, which was used to provide asurface layer on the surface of a DVD disc in Example 2, may also beutilized for surface coatings on a wide variety of materials and goodsby any known surface coating technique such as roll, slot, flow, dip,curtain, spray, and rod coatings followed by UV curing to render thecoating into the colorless solid state. In particular, an ink jet spraytechnique could be used to print a colorless image, text message, orbarcode, such as “Expired” or “Do Not Use” on the package or goods thatwould, after oxidation of the colorless LMB to the colored MB, provide aclear indication of the status of the goods stored within the package.

Such UV cured surface coatings prepared with alkoxylated monomers haveshown poor photostability: increasing levels of Sartomer monomers SR502(ethoxylated-9 trimethylol triacrylate) and CD501 (propoxylated-6trimethylol triacrylate) result in increasingly poor photostability ofTIPSOC-LBM derived methylene blue even in the presence of addedphotostabilizers and as such these coatings may not be adequate forbadge security type uses. Photostability as a coating within a lighttight bottle, package or good will be adequate for tamper proof oranaerobic seal monitors.

Oxygen and redox indicating surface coatings that do not require UVcuring, may be formulated by dissolving TIPSOCLMB, an appropriatedeblocking catalyst, and a reducing agent timing additive if needed,into a suitable volatile inert solvent based polymer solution. Any ofthe coating methods mentioned above may be used to control the coatingthickness and the surface coating is rendered into the colorless solidstate by volatilization of the solvent. Suitable volatile inert solventsinclude, but are not limited to, acetone, MEK, acetonitrile, methylenechloride, dichloroethane, aliphatic and aromatic hydrocarbons. Solventsand additives that are more aggressive to initiating the deblockingreaction of TIPSOCLMB may be incorporated by utilizing in-line mixingtechniques that are well known to those skilled in the art. Likewise,for longer term solution stability, polymer materials must be selectedfrom those would be inert for initiating the deblocking reaction ofTIPSOCLMB; such polymer materials would include acrylate polymers suchas polymethylmethacrylate and its higher homologues and copolymers,aliphatic polymers such as TOPAS, polyesters, vinyl resins, and mixturesthereof. A wider selection of polymer materials that may increase therate of deblocking of TIPSOCLMB may be incorporated into the coating byutilizing in-line mixing techniques that are well known to those skilledin the art. Such polymer materials for in-line blend applications mayinclude virtually all known functional groups, including, but notlimited to carboxylic acid, sulfonic acid, amine, and hydroxyl groups.

EXAMPLE 3

Formulation of Sandwich Coating Fluid Containing TIPSOCLMB

This example incorporates the use of a photostabilizer(polyhydroxystyrene) to prevent photobleaching of the oxidizedindicating label or marking. Excessive photobleaching of the methyleneblue chromophore in a strong light source would result in a negativeindication of exposure to oxygen even though such exposure had occurredand thus lead to defeat of the indicating marker or time limitingmechanism of a timed badge.

This example also incorporates the use of a reducing agent which resultsin an increase in time before the expired signal is generated. Stannousethylhexanoate has been found to be effective when used at a weightpercent level of 0-10%, with a preferred level of 0-5%. Higher levelstend to cause coating defects in the present formulation, but higherlevels may become more usable with formulation variations knowledgeableto those skilled in the art. Component: Wt. grams Final Wt % Part A:Sartomer SR440 32.50 10.08% Sartomer SR238 65.00 20.16% Sartomer SR49597.50 30.24% PHS8EO1 39.00 12.09% Tinuvin 292 0.75 0.23% Irgacure 8195.20 1.61% Part B: Sartomer SR339 65.00 20.16% TIPSOC-LMB 4.50 1.40%Part C: Stannous 2-Ethylhexanoate 13.00 4.03%

Part A was prepared by first combining the Sartomer monomers SR440,SR495and SR231 (Sartomer Company, 502 Thomas Jones Way, Exton, Pa.19341), followed by the dissolution of the polyhydroxystyrene (PHS-8EO1;Triquest, L. P., 14785 Preston Road, Dallas, Tex. 75254-9123) withstirring and slight warming to 60° C. With continued stirring, theTinuvin 292 (Ciba Specialty Chemcals, 540 White Plains Road, Tarrytown,N.Y. 10591-9005) was then added, followed by the Irgacure 819 (CibaSpecialty Chemcals, 540 White Plains Road, Tarrytown, N.Y. 10591-9005).The mixture was stirred in the dark until homogeneous. Part A is verystable and may be stored in the dark at about room temperature forseveral months before use. Part B was prepared by dissolving TIPSOC-LMBin Sartomer SR339 under a nitrogen atmosphere with slight warming to 50°C. Part C comprises a single component and then requires no treatmentother than weighing.

The full active adhesive was then prepared by the addition of Part Cinto Part B followed by vigorous mixing at room temperature, and thenadding this mixture into Part A followed by vigorous mixing at roomtemperature. The adhesive was used within four hours of mixing byspreading or applying the fluid mixture between two substrates, one ofwhich must be of sufficient optical transmission to allow curing with atypical UV light source used for such purposes. The fluid mixtureapplication processes include spin coating of small objects, such as hasbeen previously described for DVD discs, and various laminationtechniques, as are known to those skilled in the art, for themanufacture of roll or sheet goods.

The advantage of laminated structures is the added ability to furthercontrol timing of the indicator system by restricting the diffusion ofoxygen to the laminating adhesive that now contains LMB afterdeblocking. The oxygen permeability of each side of the laminatedstructure may be varied over a wide range by those skilled in the art.

A substrate is centered data side up on the turntable as stated above.The turntable is held stationary while the fluid is dispensed on thesubstrate in a manner creating drops with a syringe roughly 3.about.5mm. These are evenly spaced about 3 mm apart on a The substrate to bebonded is then placed facing the diameter of 30.about.40 mm. Thesubstrate to be bonded is then placed facing the solution and slightlybowed away from the bottom substrate by the edges. The substrate will belowered at angle until the first contact point between a fluid drop andtop substrate occurs. To avoid air bubble and entrapped air andsubsequent bubbles the substrate is rotated in a clockwise rotationwhile keeping it slightly bent under light pressure until each of thefluid drops begins to form a capillary bridge ring. Once the capillaryring is completed, the top substrate is released and the capillaryaction will continue. We can wait for the capillary flow to cover thesurface, or we can spin the substrate at 100 rpm's. At this point theturntable can be turned on and rotated at about 500 rpm's for 5 seconds.The substrate can then be wiped and then be UV cured. At this point, thesubstrate is subjected to about 20 about 30 flashes from a Norlite 400xenon flash lamp at it max setting. The time between flashes is dictatedby the charging of the flash lamp, but should be sufficient as to notinduce added stress from heat generated in the cure (typically 5seconds). This process will yield a clear, uncolored, fully curedacrylate film. Other substrates are prepared with similar acrylateformulations that contain either no Dabco or 10 times the amount ofDabco described in Example 1.

Controlling the Timing of the Reaction

One benefit of this embodiment of the present invention is that for abroad class of stimuli, such as those requiring diffusion of a substancethrough a barrier layer, incorporating the reactive material in sandwichand/or between two substrates results in substantial advantagesregarding the timing characteristics of the reaction.

One method of achieving the above mentioned desirable timingcharacteristics is to use a reactive material between two substratematerials, which reacts with a substance that needs to diffuse throughthe substrates. For example, if the reactive material is sensitive tooxygen, there will be an extended period in which there will be noreaction while the oxygen diffuses through at least one substrate. Onceoxygen reaches the reactive material, the resulting reaction can befast, resulting in rapid change in the reactive material.

When oxygen is used as the diffusing substance, it may be necessary toremove oxygen that dissolves in the good and/or service and/or itemand/or package during the different stages of its manufacture. This canbe done, for example, by storing the good and/or service and/or items ina vacuum or in an oxygen free environment for an appropriate period oftime. It has been established theoretically and experimentally that 24hours is an adequate period to extricate oxygen dissolved in a 0.6 mmthick polycarbonate substrate. Alternatively, if a blocked reactivematerial is used as described earlier, all oxygen scavenging material,such as iron or an organometallic compound, can be used to extricateoxygen from the optical good and/or service and/or item and/or packagebefore the blocked reactive material unblocks. This method has severalmanufacturing advantages; for example, it can avoid oxygen extricationduring manufacturing of the good and/or service and/or item and/orpackage by including the oxygen scavenging material in the packaging ofthe good and/or service and/or item, which allows the extrication of theoxygen to take place after the good and/or service and/or item ismanufactured and packaged.

Another means for controlling the timing of the expiration of the goodand/or service and/or item is to include in or adjacent to the reactivematerial a finite, controlled quantity of an appropriate protectivesubstance, such as all antioxidant in the case that the reactivematerial reacts with oxygen. The protective substance would prevent thereactions that cause the good and/or service and/or item and/or packageto change indicator state until such time as the anti-oxidant wasconsumed, at which time the good and/or service and/or item and/orpackage indicator would rapidly degrade. For example, an organometalliccompound that reacts with oxygen can be packaged with the good and/orservice and/or item to protect the good and/or service and/or item fromoxidation while in the package. Alternatively, the organometalliccompound can be incorporated into the substrate, thus continuing toprotect the metal layer for a period of time alter the package has beenopened.

Depletion of a protective substance could be combined with diffusion ofthe triggering substance through a substrate of the good and/or serviceand/or item and/or package, to result in longer delays before the goodand/or service and/or item expires, or to enable finer control of thecharacteristics of the expiration process.

Example of Antioxidant in Reactive Layer (See Example 3)

Alternatively, the protective substance may be a reducing agent that maybe incorporated into the reactive bonding material itself. Alternatereducing agents might include other Sn (II) compounds which would besoluble in the UV cure formulation, such as acetylacetonate chelates,fatty alpha-aminoacid chelates and salts; soluble iron (II) compounds,such as fatty carboxylates and chelates such as acetylacetonates;ascorbic acid and its derivatives such as ascorbyl palmitrate;hydroquinones, such as 2,5-di-tert-amylhydroquinone;alkylhydroxylamines; hydrazines; dithionates with a solubilizingcounterion; reducing saccharides such as glucose; alpha-hydroxyketones,such as acetol; appropriately substituted boron and silicon hydrides.Although many of these materials are difficultly soluble in currentactive adhesive formulations, a more expeditious choice of monomers andoligimers might allow the use of one of these alternate reducing agentswhile still providing good adhesive and dye stabilization properties.

Preventing Photobleaching of Expired Good and/or Service and/or Items

Polyhydroxystyrenes (for example, PHS-XE-01, available from ChemFirstElectronic Materials L. P, 14785 Preston Road, Suite 480, Dallas, Tex.75254-912), have been found to be effective photostabilizers for azinedyes in UV cured adhesives. Enhanced photostabilization of azine dyesoccurs in formulations in which the selected monomer mixture has a morehydrophobic character. The hydrophobic character may be characterized inthis system by alcohol group content; low levels of alcohol groupsresult in a more hydrophobic matrix compared to higher levels ofalcohol. In one experiment, the ratio of monomers (Sartomer SR395,isodecyl acrylate; Sartomer SR495, caprolactone acrylate; and SartomerSR349, ethoxylated bisphenol A diacrylate) was varied such that theweight % of SR495 (hydroxy containing monomer) ranged from 39% to 62%.Improved photostability of the methylene blue (produced via in-situdeblocking and oxidation of TIPSOC-LMB) in the respective cured bondingadhesives was found in the formulation with the lower alcohol content.

EXAMPLE A (See Example 3)

An additional benefit of a polymeric light stabilizer is that a higherconcentration of photostabilizer may be incorporated into the adhesivemixture with the upper limit to be found only as a result of highviscosity. Usable adhesives with concentrations of PHS as high as 35% bywt have been formulated; conventional monomeric phenolic organiccompounds tend to form crystals which have been found to limit theirsolubility and thus their utility in active adhesive formulations.

A polymeric phenol made by the acid catalyzed addition of hydroxyphenylcarbinol, known as PHS-B available from ChemFirst Electronic MaterialsL. P, has been also been found to be very effective as a photostabilizerin these systems. Copolymers of 4-hydroxystyrene such as with styreneand butyl acrylate also show photostabilization effects in bondingresins; many copolymers would be expected to be effective here.

The photostability of azine dyes other than methylene blue is alsoimproved with the addition of polyhydroxystyrene polymers.

EXAMPLE B (See Example 3)

Additionally, photostability can be improved by adding resorcinolderivatives such as 4-hexylresorcinol or 4-cholorresorcinol.Photostability may be further improved by increasing the TIPSOCconcentration to the good and/or service and/or item.

Accordingly, the present invention has been described at some degree ofparticularity directed to the exemplary embodiments of the presentinvention. It should be appreciated, though, that the present inventionis defined by the following claims construed in light of the prior artso that modifications or changes may be made to the exemplaryembodiments of the present invention without departing from theinventive concepts contained herein.

Equivalents

As will be apparent to those skilled in the art to which the inventionpertains, the present invention may be embodied in forms other thanthose specifically disclosed above without departing from the spirit oressential characteristics of the invention. The particular embodimentsof the invention described above are, therefore, to be considered asillustrative and not restrictive. The scope of the invention is as setforth in the appended claims rather than being limited to the examplescontained in the foregoing description.

1. A colorimetric indicator system comprising: a reactive material, saidreactive material has a first state that is substantially unreactive tothe presence of oxygen and a second state that is substantially reactiveto the presence of oxygen; wherein said first state comprises at leastone blocked dye derived by the reduction of a dye selected from azines,oxazines, thiazines, and combinations thereof; and said second statecomprises said at least one blocked dye unblocked; wherein said at leastone blocked dye is derived by the reduction of a dye having the formula(I):

wherein Y represents O, S, or NR₁₂, wherein R₁₂ is selected fromhydrogen, alkyl, or aryl groups; Z is selected form NR₉ R₁₀, OR₁₁,hydrogen, alkyl, aryl, azo, or fused aromatic components; R₁, R₂, R₃,R₄, R₅, and R₆ each independently is selected from hydrogen, alkyl,aryl, nitro, or fused aromatic groups; R₇, R₈, R₉, R₁₀, and R₁₁ eachindependently is selected from hydrogen, alkyl or aryl groups; and Xrepresents a halogen or other suitable anion; wherein said reactivematerial is affixed to and/or integral with at least one of a packagewall, a packaged object, an identification badge, and a substrate. 2.The colorimetric indicator system according to claim 1, furthercomprising a reducing agent.
 3. The colorimetric indicator systemaccording to claim 2, wherein said reducing agent is stannousethylhexanoate.
 4. The colorimetric indicator system according to claim2, wherein said reducing agent is selected from soluble Sn (II)compounds, soluble iron (II) compounds, reducing saccharides, ascorbicacid and its derivatives, hydroxylamines, hydrazines, dithionates with asolubilizing counter ion, alpha-hydroxyketones, appropriatelysubstituted boron and silicon hydrides, and combinations thereof.
 5. Thecolorimetric indicator system according to claim 1, further comprisingat least one basic substance.
 6. The colorimetric indicator systemaccording to claim 5, wherein at least one basic substance is selectedbased on the ability to act as an unblocking catalyst.
 7. Thecolorimetric indicator system according to claim 5, wherein said atleast one basic substance is selected based on the ability to controlthe rate the reduced form of the reactive material is oxidized.
 8. Thecolorimetric indicator system according to claim 5, wherein said atleast one basic substance is selected from a amine group.
 9. Thecolorimetric indicator system according to claim 5, wherein at least onebasic substance is 1,4-diazabicyclo[2.2.2]octane or Tinuvin
 292. 10. Thecolorimetric indicator system according to claim 1, further comprising acarrier material wherein said carrier material is selected from at leastone of thermoplastic acrylic polymers, polyester resins, epoxy resins,polythiolenes, ultraviolet cured organic resins, polyurethanes,thermosettable acrylic polymers, alkyds, vinyl resins, and combinationsthereof.
 11. The colorimetric indicator system according to claim 1,further comprising a cover layer wherein said cover layer overlays saidreactive material.
 12. The colorimetric indicator system according toclaim 1, further comprising a lamination layer wherein said laminationlayer overlays said reactive material.
 13. The colorimetric indicatorsystem according to claim 1, wherein said substrate is selected from aroll material, such as plastic, metal, or paper.
 14. The colorimetricindicator system according to claim 1, wherein said reactive material isin the form of a particulate.
 15. The colorimetric indicator systemaccording to claim 1, wherein said reactive material istriisopropylsilyloxycarbonyl leucomethylene blue (II):


16. The colorimetric indicator system according to claim 1, wherein saidreactive material is enclosed in an anaeorbic package.
 17. Acolorimetric indicator system used for a packaging applicationcomprising: a reactive material, said reactive material has a firststate that is substantially unreactive to the presence of oxygen and asecond state that is substantially reactive to the presence of oxygen;wherein said first state comprises at least one blocked dye derived bythe reduction of a dye and combinations thereof; and said second statecomprises said at least one blocked dye unblocked; wherein said at leastone blocked dye is derived by the reduction of a dye having the formula(III):

wherein R₁-R₄, R₇ each independently is selected from hydrogen, alkyl,aryl, alkoxy, halogens, hydroxyl, CN, substituted thiols, SO₂ alkyl, SO₂aryl, CO₂ alkyl, or CO₂ aryl, where alkyl and aryl can be substitutedand may include atoms necessary to complete an aromatic or acyclic ringsystem, which may contain heteroatoms and substitution; R₅, R₆ eachindependently is selected from hydrogen, alkyl, aryl, alkoxy, wherealkyl and aryl can be substituted an may include atoms necessary tocomplete an aromatic or acyclic ring system; and wherein said reactivematerial is affixed to and/or integral with at least one of a packagewall, a packaged object, an identification badge, and a substrate. 18.The colorimetric indicator system according to claim 17, furthercomprising a reducing agent.
 19. The colorimetric indicator systemaccording to claim 18, wherein said reducing agent is stannousethylhexanoate.
 20. The colorimetric indicator system according to claim18, wherein said reducing agent is selected from soluble Sn (II)compounds, soluble iron (II) compounds, reducing saccharides, ascorbicacid and its derivatives, hydroxylamines, hydrazines, dithionates with asolubilizing counter ion, alpha-hydroxyketones, appropriatelysubstituted boron and silicon hydrides, and combinations thereof. 21.The colorimetric indicator system to claim 17, further comprising atleast one basic substance.
 22. The colorimetric indicator systemaccording to claim 21, wherein said at least one basic substance isselected based on the ability to set as an unblocking catalyst.
 23. Thecolorimetric indicator system according to claim 21, wherein said atleast one basic substance is selected based on the ability to controlthe rate the reduced form of the dye is oxidized.
 24. The colorimetricindicator system according to claim 21, wherein said at least one basicsubstance is selected from an amine group.
 25. The optical mediumaccording to claim 21, wherein said at least one basic substance isselected from an least one of imidazole, diisopropylamine, dodecylamine,tripentylamine, tinuvin 292, aminohexanol, 4-(2-aminoethyl)-morpholine,dihexylamine, diisobutylamine, 1-(2-aminoethyl)-piperazine,aminoethoxyethanol, dioctylamine, and combinations thereof.
 26. Thecolorimetric indicator system according to claim 17, further comprisinga carrier material wherein said carrier material is selected form atleast one of thermoplalstic acrylic polymers, polyester resins, epoxyresins, polythiolenes, ultraviolet cured organic resins, polyurethanes,thermosettable acrylic polymers, alkyds, vinyl resins, and combinationsthereof.
 27. The colorimetric indicator system according to claim 17,further comprising a cover layer wherein said cover layer overlays saidreactive material.
 28. The colorimetric indicator system according toclaim 17, further comprising a lamination layer wherein said laminationlayer overlays said reactive material.
 29. The colorimetric indicatorsystem according to claim 17, wherein said substrate is selected from aroll material, such as plastic, metal, or paper.
 30. The colorimetricindicator system according to claim 17, which said reactive material isin the form of a particulate.
 31. The optical medium according to claim30, wherein said at least one blocked dye is form the reduction of2-arylamino-1,4-naphthoquinone type dyes (IV).


32. The colorimetric indicator system according to claim 17, whereinsaid reactive material is enclosed in an anaerobic package.